Fluent Overview Ahmadi/Nazridoust ME 437/537/637

Fluent Overview Ahmadi/Nazridoust ME 437/537/637

Fluent Overview Ahmadi/Nazridoust ME 437/537/637  Solution Parameters Choosing the Solver Choosing the Solver Discretization Schemes Discretization Schemes  Initialization  Convergence Monitoring Convergence Monitoring Convergence Stability Stability Setting Under-relaxation Setting Under-relaxation Setting Courant number Setting Courant number Accelerating Convergence Accelerating Convergence  Accuracy Grid Independence Grid Independence Adaptation Adaptation Set Solution Parameters Initialize Enable Solution Monitors Calculate a Solution Modify the Solution Parameters or the Mesh Converged? No Yes Accurate? Stop

Fluent Overview Ahmadi/Nazridoust ME 437/537/637  Import (scale) the mesh file  Select physical models  Define material properties  Prescribe operating conditions  Prescribe boundary conditions  Provide an initial solution  Set solver controls  Set up convergence monitors  Compute and monitor solution Menu is laid out such that order of operation is generally left to right.

Fluent Overview Ahmadi/Nazridoust ME 437/537/637  Mouse button functionality depends on solver and can be configured in the solver Display Menu  Mouse Buttons... Display Menu  Mouse Buttons...  Default Settings: 2D Solver 2D Solver Left button translates (dolly) Left button translates (dolly) Middle button zooms Middle button zooms Right button selects/probes Right button selects/probes 3D Solver 3D Solver Left button rotates about 2-axes Left button rotates about 2-axes Middle button zooms Middle button zooms Right button selects/probes Right button selects/probes

Fluent Overview Ahmadi/Nazridoust ME 437/537/637  Components are defined in preprocessor Cell = control volume into which domain is broken up Cell = control volume into which domain is broken up computational domain is defined by mesh that represents the fluid and solid regions of interest. computational domain is defined by mesh that represents the fluid and solid regions of interest. Face = boundary of a cell Face = boundary of a cell Edge = boundary of a face Edge = boundary of a face Node = grid point Node = grid point Zone = group of nodes, faces, and/or cells Zone = group of nodes, faces, and/or cells Boundary data assigned to face zones. Boundary data assigned to face zones. Material data and source terms assigned to cell zones. Material data and source terms assigned to cell zones. face cell node edge 3D mesh cell center 2D mesh node face cell

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… File Menu  Read  Case File Menu  Read  Case

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to…  Grid Menu  Check  Grid Menu  Scale  Grid Menu  Translate  Fluent assumes that all physical dimensions are initially in meters.  The default unit system in Fluent is Metric (SI) units.

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Display Menu  Grid Display Menu  Grid

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Define Menu  Models  Solver Define Menu  Models  Solver Define Menu  Models  Viscous Define Menu  Models  Viscous

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Define Menu  Materials  Fluent Database Define Menu  Materials  Fluent Database  Physical models may require additional material properties need to be defined.  Single-Phase, Single Species Flows Define fluid/solid properties Define fluid/solid properties Real gas model Real gas model Multiple Phase Flows (Single Species) Multiple Phase Flows (Single Species) Define properties for all fluids and solids. Define properties for all fluids and solids.  Multiple Species (Single Phase) Flows Mixture Material concept employed  Mixture properties (composition dependent) defined separately from constituent’s properties.  Component properties must be defined.

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Define Menu  Materials  Fluent Database Define Menu  Materials  Fluent Database

Fluent Overview Ahmadi/Nazridoust ME 437/537/637  To formulate a problem that results in a unique solution, the relevant variables at the domain boundaries must be defined. Specifying velocity, temperature and pressure or fluxes of mass, momentum, energy.  Defining boundary conditions involves: i. identifying the location of the boundaries (e.g., inlets, walls, symmetry) ii. supplying information at the boundaries

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Define Menu  Boundary Conditions  Select Zones  Boundary Condition Types of External Faces General: Pressure inlet, Pressure outlet General: Pressure inlet, Pressure outlet Incompressible: Velocity inlet, Outflow Incompressible: Velocity inlet, Outflow Compressible flows: Mass flow inlet, Pressure far- field Compressible flows: Mass flow inlet, Pressure far- field Special: Inlet vent, outlet vent, intake fan, exhaust fan Special: Inlet vent, outlet vent, intake fan, exhaust fan Other: Wall, Symmetry, Periodic, Axis Other: Wall, Symmetry, Periodic, Axis  Boundary Condition Types of Cell ‘Boundaries’ Fluid and Solid Fluid and Solid  Boundary Condition Types of Double-Sided Face ‘Boundaries’ Fan, Interior, Porous Jump, Radiator, Walls Fan, Interior, Porous Jump, Radiator, Walls

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Define Menu  Boundary Conditions  Select Zones

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Solve Menu  Initialize  Initialize Solve Menu  Initialize  Initialize

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Solve Menu  Monitors  Residuals Solve Menu  Monitors  Residuals The convergence of solution can also be changed The convergence of solution can also be changed

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Solve Menu  Iterate  Iterate Solve Menu  Iterate  Iterate

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 How to… Display Menu  Contours Display Menu  Contours Display Menu  Vectors Display Menu  Vectors

Fluent Overview Ahmadi/Nazridoust ME 437/537/637 Flow in a Channel  Steady State  Inlet Velocity is known  Outlet is open to atmospheric pressure  No Slip on all walls  Fluid is Water  Desired Grid Resolution is 1500 Hexahedral Cells 60cm 15cm x-Velocity = 0.85 m/s y-Velocity = 0.00 m/s Outflow